Back in the day when lyniching were done, there was a just alternative of bringing the offender to trial by court and able minded jury. I also think that lynching is particularly cruel and inhumane form of execution. It may involve all sort of torture methods such as tarring, lashing, strangulation, breaking of bones. And most importantly, any man has the right for a fair trial.
I maintain the opinion that it is just to lynch a person who was caught on the on the act of committing a capital crime if the situation is that the situation is such that he would be shielded from fair trial and proper penalty by court and politics. That is the case for example in Israel, where an Arab murderer terrorist can expect to be spend prison time where the state provides him with the free high education opportunity and eventual freedom due to political settlements and trading of bodies in exchange for live murderers.